Odorless solvent naphtha composition of improved corrosivity to copper



United States Patent 'ODORLESS SOLVENT NAPHTHA COMPOSITION OF IMPROVED CORROSIVITY TO COPPER Ellis K. Fields, Chicago, Ill., and Allen E. Brehm, Griflith, Ind., assignors to Standard Oil Company, Chicago, 111., a corporation of Indiana No Drawing. Application October 5, 1954 Serial N0. 460,510

9 Claims. (Cl. 252-392) ing the pyrrole types.

ever, these naphthas also must be essentially free of corrosivity toward copper as measured by the copper strip test. Even though these naphthas are essentially free of organo-sulfur compounds and theoretically should not be corrosive toward copper, it has been found that frequently odorless naphthas give a positive copper strip test, instead of the perfect strip which is required by specifications.

An object of the invention is an odorless solvent naphtha composition of improved corrosivity to copper. Other objects will become apparent in the course of the detailed description of the invention.

The objects of the invention are attained by a composition comprising essentially a petroleum naphtha boiling between about 325 F. and about 450 R, which is essentially free of olefins, aromatics and organo-sulfur compounds, as the major component, and an effective amount of an additive derived by the reaction of a hereinafter defined amine and a hereinafter defined amino-carboxylic acid.

The amino-carboxylic acids which are suitable for the I purposes of the invention are represented by the configuration: Y (0H,).o0on

cm .coon

or (II) Rmwmnooom.

wherein "x is an integer from 1 to 3 and preferably "x is 1; R is a member selected from the class consistants and heating the mixture to the desired temperature and maintaining said mixture at that temperature for the ing of (a) hydrogen (c arN (crime OOH and wherein y and "2. isan integer from 1 to 3.

is an integer from 2 to 3 and preferably 2; A

" room temperature and may be utilized as an additive Iminodiacetic acid is an example wherein R is hydrogen and x is 1. Ethylenediaminetetraacetic acid is an example wherein R is member (b) and y is 2 and x is l. Tetraethylenepentamineheptaacetic acid is an example where R is member (0), x is 1, y is 2 and z is 3.

The amino acids of the invention may also be described as amino aliphatic carboxylic acids wherein at least one amino nitrogen holds 2 carboxyalkyl groups.

The amines suitable for the purposes of the invention are: (l) aliphatic amines, either primary, secondary, or tertiary wherein at least one aliphatic group contains t least 8 carbon atoms, and (2) heterocyclic amines which contain at least one aliphatic substituent having at least 8 carbon atoms therein and at least one ring nitrogen has a valence which is not part of the ring structure, exclud- Illustrative examples of these amines are octylamine, decylamine, tetradecylamine, octadecylamine, dioctylamine, dioctadecylamine, stearylimidazoline, and oleylimidazoline. I v

T he'preferred amines are the fatty acid amines. Those mixtures of amines which are obtained from natural vege table oils, such as palm oil, coconut oil, soya bean oil, tall oil, and cottonseed oil are suitable; as is also the mixture of amines derived from tallow. Of even greater interest are the high molecular weight amines which are obtained as a bottoms fraction in the distillative purification of the mixture of amines prepared from tallow or coconut oil. These amines are commercially available under the designation corresponding to the amine product from the particular oil or fat, e.g., tallowamine bottoms, cocoamine bottoms, etc. The bottoms product amines have one disability in that the quality of the material is variable and therefore the amine salt of the amino-carboxylic acid produced therefrom will vary in quality-from batch to batch of the, amine bottoms material.

The amine salts of amino-carboxylic acids utilizable as hydrocarbon oil additives are readily prepared by heating the desired amine and the desired amino-carboxylic acid at a temperature below the decomposition temperature of the individual components for a suitable period of time. The temperature and the time are dependent upon the particular reactants used. In general, the temperature at which the reaction is carried out is between about 30?. C. and about 200 C.; the time needed for the reaction to be completed will be between about 15 minutes and about 3 hours. It is preferred to utilize a temperature between about 140 C. and about 180 C.; the can responding time will be dependent on the type of re actants charged.

The relative amounts of amine and amino-carboxylic acid utilized is dependent upon the number of carboxylic acid groups in the acid and also upon the degree to which the carboxylic acid groups are to be reacted. When it is desired to react all the carboxylic acid groups, it is better to operate with an excess of amine over the stoichiometric requirement. In general, the molar ratio of amine to acid is between about 0.5 and 1.5 ofthe stoichiometric requirement for reactions with all the carboxylic groups in the acid. It is preferred to operate with a molar ratio of amine and amino-carboxylic acid such that all the carboxylic groups will be reacted, i.e., at least the stoichiometric requirement.

The amine salt of amino-carboxylic acid is readily prepared by admixture of the desired amounts of the reactnecessary time. The appearance of the reactants changes when the reaction begins and completion of the reaction is observed visually by disappearance of the individual reactants. The reaction product mixture is cooled to the reaction product mixture.

carried out by treating the mixture with a solvent, such .as benzene or hexane, filtering to remove the insoluble I I material and recovering the purified reaction product, i.e., the amine; salt of amino-carboxylic acid, by evaporating I organo-sulfur compounds.

order of 0.01 weight percent of total sulfur is considered to be essentially free of organo-sulfur compounds- I The I I seesaw without further treatment. However, when an excess of one reactant'has: been used, it'may bedesirable to purify. I

This purification is readily away-the solvent.

1 mole) and 48g, (0.155 mole) of Armeen T'were stirred at 150 C. for 30 minutes.

Theodorless naphthas which form the major component 1 I of the composition of'the invention arepetroleum naphthas'which are essentially free of olefins,, aromatics and A naphtha'containing on the.

petroleum naphthas suitable for odorless naphtha use boil. between about 325 'F. and about 450 F.; More usually they. boil'in the rangebf=350 F. to 425F. I I I I The odorlessnaphthas may be derived by suitable I I treatment from a straight run naphtha from the distilla-. tion of crude or may be derived by suitable treatment irom naphtha boiling range material produced in the I various polymerization or alkylation processes. The

hea'vy alkylate derived by the. acid catailyzed alkylation; of

:,=;In this example, the amine was purchased as Alro- I I amine S. I This materialsis; an imidazoline derived from.

isobutane and bntylenes' is a particularly suitable: source I of odorless naphtha. The sulfuric acid catalyzed alkylate is particularly suitable. A product of the desired characteristics is obtainable: byhydrogenating the poly- I mer obtained bypolymerization of-propylene and/or butylenes.

Thus the very best quality odorless naphtha produced- The defined amine salts of amino-carboxylicacid is present in an amount sulficient to improve the corrosivity toward copper.

acid is utilized. The particular amount used is dependent on the particular use of the composition, but in general will be between about 0.005% and about 0.5% by weight of the composition. More usually the usage will be between about 0.01% and 0.1% by weight.

Examples of the defined amine salts of amino-carboxylic acids are set out below. Illustrations of the compositions containing various amounts of illustrative examples and the beneficial results derived from the presence of the defined salt in naphtha are set out as determined by various tests. It is to be understood that the examples of the defined amine salts of amino-carboxylic acids and the illustrative naphtha compositions containing these salts are illustrative only and do not limit the scope of the invention.

SALT 1 In this example, the amine utilized was principally t-octadecylamine sold under the name of Primene JM-R. 100 g. of this amine and 20 g. of ethylenediaminetetraacetic acid were stirred at 165 C. for 10 minutes. The product was clear orange colored viscous liquid containing 5.47% nitrogen and was soluble in gasoline.

SALT 2 In this example, the amine used is sold by Armour & Co. under the name, Cocoamine Bottoms. This material is the bottoms product from the distillation of the spectrum of amines made from coconut oil. 150 g. of the cocoamine bottoms and 25 g. of ethylenediaminetetraacetic acid were stirred at 148 C. for 15 minutes. The product was diluted with 300 ml. of hexane and filtered. The hexane was removed by evaporation. The brown waxy solid product was completely soluble in gasoline and lube oil. A yield of 173 g. of product containing 2.99% nitrogen was obtained.

and a molecular'weight of 360. 43.2 g. (0.12 mole) of SALT 3 The amine utilized in this example is sold by Armour I & Co. under the designation Armeen T. This material I I isprincipally octad'ecylam'in'e and has a molecular weight of 310. Ethylenediaminetetraacetic acid-42.5 g., (0.043

a clear lightbrown liquid which contained-7.42% nitrogen'and had'a molecular weight of'103 '3. This material was very soluble in naphtha.

' SALT 4 The amine in this example-is sold by Armour & Co. I under the designation Duorneen-S. This amine has the structure RNH QCH MNH where Ris an aliphatic. group I I containing 18 carbonatorns. I 0.86 mole ofDuomeen S I and 0.46 mole of' ethylenediaminetetraacetic acid were stirred at 155 C. for 20rniuutes. The productwas an. I I I orange-yellow in color and contained 7.91% nitrogen and I was: soluble in gasoline. I

stearic acid and has the following: structure: I

I N-CH;

r wro thisimidaz'oline and 8.76 'g.,' (0.03 mole) of ethylcnedi- I Generally only I a very small amount of amine salt of amino-carboxylic 4D which had; 3.55% nitrogen and :a molecularweight of. I Q

'aminetetraacetic acid were stirred at:150: C.- for 15 min: I I I The product weighed 51 g. andwas a clear brown I I liquid containing 8 .28% nitrogen. I The product was so1-' utes.

uble in naphtha.

i i SALT 6 I Irninodiacetic acid (0.1: mole.) and 0.2 mole of tel lowamine bottoms (purchased from AIII10111"& Cor-- 421) were stirred at about 170 C. The reaction product was a light brown waxy solid which was completely soluble in gasoline. The product of this reaction contained 5.06% nitrogen.

Examples I In this method, a number of zero indicates a perfect strip and the higher the number, the more corrosive the oil.

The odorless naphtha utilized in the tests was obtained from a heavy alkylate produced by the cold-sulfuric acid catalyzed alkylation of isobutane and refinery butylenes.

' This heavy alkylate boiled over the range:

ASTM Dist:

Initial352 F. 50%--386 F. Maximum-576 F.

and had a total sulfur content of 0.025 weight percent. The heavy alkylate was distilled to take overhead 70 volume percent. This overhead, which boiled between 340 F. and 403 F. had a sulfur content of 0.01 weight percent and was the feed to the process for producing a product odorless naphtha. The feed naphtha was treated in a batch agitator with 10 lbs. per bbl. of 98% black sulfuric acid. The treated naphtha was given two rain washes where 50 volume percent of water in each wash was drizzled on to the surface of the treated naphtha in such a way that no agitation of the naphtha occurred.

The reaction product. was I At the completion of each rain wash, the lower aqueous layer was removed. By this technique, hydrolysis of the pepper sludge is minimized. The rain wash naphtha was given a conventional water wash using 5 volume percent of water. The washed naphtha was neutralized by contacting it with 5 volume percent of a 5% aqueous NaOH solution. The final water wash with 5 volume percent of water produced a product odorless naphtha. In all of the contacting steps, the naphtha and acid or aqueous solution were agitated by means of air blowing.

The odorless naphtha as produced above was utilized with various of the defined amine salts in tests which are set out in Table I below.

Table I Additive The data show that an improvement in the copper strip of the naphtha is obtained with the addition of even a slight amount of material. The perfect strip of 0+ is obtainable by the use of about 0.01 weight percent of the defined amine salt for each unit by which the copper strip number is to be reduced.

It is believed that the positive copper strip obtained in the odorless naphtha produced as above is the result of peroxide formation. Tests carried out on naphthas produced under conditions which excluded substantially all free oxygen show that the copper strip of the freshly produced product naphtha was 0+. However, after standing in storage exposed to atmospheric oxygen, such naphtha deteriorates and develops a positive copper strip. These tests show that this copper strip is not due to the presence of organo-sulfur compounds. The data presented above show that the defined amine salts effectively inhibit the corrosiveness of the odorless naphtha toward copper and enable the production of an odorless naphtha having a perfect strip, i.e-, 0+, from a naphtha which gives a positive copper strip number.

'l hus having described the invention, what is claimed is:

1. A composition consisting essentially of a petroleum naphtha boiling between about 325 F. and about 450 F. which is essentially free of olefins, aromatics and onganosulfur compounds, and between about 0.005% and about 0.5% of an amine salt of an amino-carboxylic acid obtained by reacting, at a temperature between about 30 C. and about 200 C., a molar ratio of amine to acid between about 0.5 and 1.5 of the stoichiometric requirement to react all the carboxylic groups in the acid, said amine 5 being selected from the class consisting of (1) aliphatic amines wherein an aliphatic group having at least 8 carbon atoms is present and (2) imidazoline containing an 6 aliphatic substituent having at least 8 carbon atoms is present, with said amino-carboxylic acid having the configuration (oHmc 0 0H (cm) 20 0 OH wherein R is selected from the class consisting of hydrogen and (CH2):COOH

(0H,) 20 0 OH wherein x is an integer from 1 to 3, y is an integer from 2 to 3, said composition being characterized by a copper strip number of 0+.

2. The composition of claim 1 wherein said salt is ob tained by reacting cocoamine bottoms and ethylenediaminetetraacetic acid at a temperature between about C. and C.

3. The composition of claim 1 wherein said salt is obtained by reacting an aliphatic amine having about 18 carbon atoms in each aliphatic group and ethylenediaminetetraacetic acid at a temperature between about 140 C. and 180 C.

4. The composition of claim 1 wherein said amine is tallowamine bottoms.

5. The composition of claim 1 wherein said amine is stearylimidazoline.

6. The composition of claim 1 wherein said acid is tetraethylenepentamineheptaacetic.

7. The composition of claim 1 wherein said acid is iminodiacetic.

8. The composition of claim 1 wherein said salt is present in an amount between about 0.01 and about 0.1 weight percent.

9. The composition of claim 1 wherein said naphtha is derived from the product of acid catalyzed alkylation of isobutane and butylenes.

References Cited in the file of this patent UNITED STATES PATENTS 2,412,945 Bersworth Dec. 24, 1946 2,564,129 Rotelli Aug. 14, 1951 2,689,828 Smith et al. Sept. 21, 1954 2,700,612 Chenicek Jan. 25, 1955 2,718,502 Rocchini Sept. 20, 1955 2,773,879 Sterlin Dec. 11, 1956 2,790,780 Spivak et a1 Apr. 30, 1957 2,805,203 Knapp et al. Sept. 3, 1957 OTHER REFERENCES Sequestrene, page 3, published by Geigy Ind. Chemical, New York (1952). 

1. A COMPOSITION CONSISTING ESSENTIALLY OF A PETROLEUM NAPHTHA BOILING BETWEEN ABOUT 325*F. AND ABOUT 450*F. WHICH IS ESSENTIALLY FREE FO OLEFINS, AROMATICS AND ORGANOSULFUR COMPOUNDS, AND BETWEEN ABOUT 0.005% AND ABOUT 0.5% OF AN AMINE SALT OF AN AMINO-CARBOXYLIC ACID OBTAINED BY REACTING AT A TEMPERATURE BETWEEN ABOUT 30*C. AND ABOUT 200*C., A MOLAR RATIO OF AMINE TO ACID BETWEEN ABOUT 0.5 AND 1.5 OF THE STOICHIOMETRIC REQUIREMENT TO REACT ALL THE CARBOXYLIC GROUPS IN THE ACID, SAID AMINE BEIN SELECTED FROM THE CLASS CONSISTNG OF (1) ALIPHATIC AMINES WHEREIN AN ALPHATIC GROUP HAVING AT LEAST 8 CARBON ATOMS IS PRESENT AND (2) IMIDAZOLINE CONTAINING ANY ALIPHATIC SUBSTITUENT HAVING AT LEAST 8 CARBON ATOMS IS PRESENT, WITH SAID AMINO-CARBOXYLIC ACID HAVING THE CONFIGURATION 